Article stringing machines



Feb. 27, 1968 A. G. LOVELL ARTICLE STRINGING MACHINES Filed Feb. 1, 1966 United States Patent 3,370,558 ARTECLE STRENGING MAQHINES Aifred G. Lovell, Hanover, Mass., assignor to United Shoe Machinery Corporation, Boston, Mass., a corporation of New Jersey Filed Feb. 1, 1966, Ser. No. 523,982 Claims. (Cl. 112-104) The present invention relates generally to improvements in article stringing machines, and more particularly to devices in such machines for assuring the entrainment of a flexible strand at the beginning of the operating cycle of the machine.

In article stringing machines such as that disclosed in United States Letters Patent No. 3,142,896, granted Aug. 24, 1964, upon application of Charles P. Cardani et al., a curved eye-pointed needle oscillates from a rest position toward and through a workpiece to carry the leading end of a string or other flexible strand through the workpiece and then returns to its rest position. At the beginning of the needle motion toward the workpiece, before the needle pentrates the workpiece, and during penetration it is necessary that the friction provided by the eye of the needle be assisted by an auxiliary device to overcome the inertia of strand supply and resistance to the free flow of strand from guiding instrumentalities along its path. If the needle eye is not adequately assisted the needle becomes unthreaded and there is a consequent delay for rethreading before article stringing operations may be resumed.

After the article has been penetrated by the needle a considerable quantity of strand must be reeved through the eye of the needle to form a closed loop either to join two articles together or to connect .a tag to a single article. Since the size of loop may very widely according to the choice of the merchant the quantity of strand passing through the eye of the needle and through the strand entrainment device may be as great as 24".

The diameter and texture of the strand may also vary widely according to the requirements of the particular article or merchandise being processed. It is essential that an acceptable entrainment device not only ensure the entrainment of the strand of the beginning of the stringing operation but also apply minimum frictional resistance to the passage of the strand toward the eye of the needle under conditions of varying strand diameter and length.

It is accordingly an object of the present invention to improve the operating reliability of article stringing machines by assuring entrainment of a strand at the start of the operating cycle.

Another object is to provide effective control of various types of the strands in article stringing machines and more particularly to do so without imposing undue frictional resistance upon the motion of the strand through the eye of a needle and toward a workpiece.

Still another object is to provide a strand controlling device which is inexpesenve to manufacture, reliable and durable in its operation and readily replaceable when the need arises.

Yet another object is to provide for the positive entrainment of a strand by a device occupying a minrnum of space along a needle at the point of penetration of a workpiece.

In the achievement of the foregoing objects a feature of the invention relates to a strand engaging roll rotatable on the end of the spring pressed arm. The roll, in resisting a pull on the strand away from the needle eye presses the strand against an angularly oriented surface to resist movement of the strand which would otherwise cause the needle to become unthreaded. When the strand is moved toward the needle eye, however, the motion of the strand tends to carry the roll and the arm against the bias of the spring away from the angular surface and the roll provides a minimum resistance to the flow of the strand.

The foregoing objects, features and numerous advantages of the present invention will be more fully understood from the following detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary view in front elevation of an article stringing machine including a strand friction embodying the present invention;

FIG. 2 is a sectional detail view on a greatly enlarged scale showing the gripping of the strand by the friction of FIG. 1;

FIG. 3 is a fragmentary view in rear elevation illustrating the relationship of a needle, a needle guide and the strand friction device; and

FIG. 4 is a view in cross section taken along the line IVIV of FIG. 3 showing the strand friction device and its pivotal mounting on the needle guide forming a part of the machine.

Turning now to the drawings. particularly FIG. 1, the article stringing machine illustrated therein will be briefly described to provide the necessary background for a clearer understanding of the operation of strand entraining instrumentalities of the machine which is basically that disclosed in US. Patent No. 3,142,896 as later modified in US. Patent No. 3,207,106 granted Sept. 21, 1965 upon application of Herman A. Imhof. The illustrative machine comprises a curved eye-pointed needle 10 mounted on a needle carrier 12 which includes an integral pinion 14. The needle 10 is oscillated in a clockwise direction to carry a strand 16 through first and second azticles or workpieces 18 and 20 respectively and to return to the position of FIG. 1. For imparting the oscillatory motion of the needle the pinion is in mesh with a gear sector 22. The needle carrier is pivoted on a stud 24 mounted coaxially with the pinion 14 and upon which a needle guide 26 is journalled. The needle guide 26 is formed with a guideway 28 which provides a sliding fit for the needle 10 and the guide is urged toward the eye of the needle by a torsion spring 30. The articles 18 and 20 are held in stringing position against a pedestal 32 by clamps including pads 34 and 36. After the strand has been carried through the articles 18, 20 by the needle 10, the leading end is gripped by a first pincer 38. The needle is withdrawn and, after a quantity of strand has been measured on a drum 40 as in US. Patent No. 3,207,106, an intermediate portion of the strand between the article 18 and the needle eye is gripped by a second pincer 42. Thereafter the strand is out between the pincer 42 and the needle eye and the two ends of the strand passing through the articles are formed into bights around a spindle 44 supported on the pedestal 32. As in the machine of US. Patent No. 3,142,896, an eyelet is clinched on the spindle 44 to join together the ends of the strand with or without a tag.

At the start of the operating cycle of the machine as the needle 10 starts in motion toward the pedestal 32, the strand 16 is entrained by a uni-directional frictional device engaging the strand in advance of the needle eye and comprising a roller 46 rotatably supported on an arm 48 (FIGS. 3 and 4) pivoted on the needle guide 26. The pivot for the arm 48 is in the form of a shoulder screw 50 tightened into the needle guide 26 and a torsion spring 52 is provided for urging the roller 46 toward a strand engaging position. The roller 46 is rotatable on a headed stud 54 which is riveted to the arm 48. The strand 10 is engaged by the roller 46 and pressed against an angular anvil surface 56 oriented with respect to the path of the roller to provide a bite upon the strand when it is pulled in a withdrawing direction indicated by an arrow 58. The

orientation of the surface 56 is also such that the roller 46 moves quickly away from the surface when the strand is pulled in a feeding direction through and beyond the needle eye as indicated by an arrow 60. It has been found that such resistance to Withdrawal of the strand and ease of flow of the strand in the feeding direction is attained when the surface 56 defines with the releasing path of the roller 46 a gripping angle 62 of approximately 20 while engaging a strand of average diameter. The gripping angle 62 is measured between the surface 56 and a tangent to the roll 46 drawn at the intersection of the center line connecting the axis of the shoulder screw 50 and the roll.

In the drawings and particularly in FIG. 2 there is shown, exaggerated for clarity, at 64 a flattening of the strand between the roller 46 and the anvil surface 56. The increased thickness of the strand immediately in advance of the roller 46, that is between the roller 46 and a strand guiding eye 66 in the needle guide, causes the arm 48 to be carried in a counterclockwise direction as seen in FIG. 3 as the strand begins to move in the direction 60 to procomprising an arm pivoted on the needle guide, a strand engaging member mounted on the arm, resilient means urging the member toward a position of engagement with the strand in advance of the needle eye and an angularly oriented anvil surface on the needle guide in cooperative relationship with the member for frictionally engaging the strand as the needle is actuated toward the workpiece to prevent the withdrawal of the strand from the needle eye.

2. A strand friction device as in claim 1 further characterized in that the member is a roller rotatable on the arm and the resilient means is in the form of a torsion spring interposed between the needle guide and the arm.

3. A strand friction device as in claim 1 further com: prising a strand guiding eye outside the radius of cm" vature and in the plane of the needle for directing the strand into frictional engagement with the anvil surface and the member.

vide the necessary quantity of strand for an article stringa ing operation. It will also be seen from FIG. 2 that the eye 66 is pierced in the needle guide so as to direct the strand out of contact with the surface 56 when the roller 46 has been carried away from its strand restraining position to the strand withdrawal position shown in dash lines in FIG. 3. Thus as a quantity of strand is being measured, movement of the strand is resisted by minimum friction offered by the needle eye, the guiding eye 66 and the roller 46.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In an article stringing machine having a curved eye pointed needle for carrying the leading end of a strand through a workpiece and a needle guide for preventing deflection of the needle, a strand friction device References Cited UNITED STATES PATENTS 1,324,985 12/1919 Seely l 1 2-253 3,166,035 1/1965 Wiegana ;112- 104 3,183,867 5/1965 Imhof "112-1 04 JORDAN FRANKLIN, Primary Examiner.

G. V. LARKIN, Examiner. 

1. IN AN ARTICLE STRINGING MACHINE HAVING A CURVED EYE POINTED NEEDLE FOR CARRYING THE LEADING END OF A STRAND THROUGH A WORKPIECE AND A NEEDLE GUIDE FOR PREVENTING DEFLECTION OF THE NEEDLE, A STRAND FRICTION DEVICE COMPRISING AN ARM PIVOTED ON THE NEEDLE GUIDE, A STRAND ENGAGING MEMBER MOUNTED ON THE ARM, RESILIENT MEANS URGING THE MEMBER TOWARD A POSITION OF ENGAGEMENT WITH THE STRAND IN ADVANCE OF THE NEEDLE EYE AND AN ANGULARLY ORIENTED ANVIL SURFACE ON THE NEEDLE GUIDE IN COOPERATIVE RELATIONSHIP WITH THE MEMBER FOR FRICTIONALLY ENGAGING THE STRAND AS THE NEEDLE IS ACTUATED TOWARD THE WORKPIECE TO PREVENT THE WITHDRAWAL OF THE STRAND FROM THE NEEDLE EYE. 